Fix clients acquiring hosts on order creations

OpenRA.Mods.Common/Activities/MoveToDock.cs

@@ -24,16 +24,37 @@ namespace OpenRA.Mods.Common.Activities
 		IDockHost dockHost;
 		readonly INotifyDockClientMoving[] notifyDockClientMoving;
 		readonly MoveCooldownHelper moveCooldownHelper;
+		readonly bool forceEnter;
+		readonly bool ignoreOccupancy;
 
-		public MoveToDock(Actor self, Actor dockHostActor = null, IDockHost dockHost = null)
+		public MoveToDock(Actor self, Actor dockHostActor = null, IDockHost dockHost = null,
+			bool forceEnter = false, bool ignoreOccupancy = false)
 		{
 			dockClient = self.Trait<DockClientManager>();
 			this.dockHostActor = dockHostActor;
 			this.dockHost = dockHost;
+			this.forceEnter = forceEnter;
+			this.ignoreOccupancy = ignoreOccupancy;
 			notifyDockClientMoving = self.TraitsImplementing<INotifyDockClientMoving>().ToArray();
 			moveCooldownHelper = new MoveCooldownHelper(self.World, self.Trait<IMove>() as Mobile) { RetryIfDestinationBlocked = true };
 		}
 
+		protected override void OnFirstRun(Actor self)
+		{
+			if (IsCanceling || dockClient.IsTraitDisabled)
+				return;
+
+			// We were ordered to dock to an actor but host was unspecified.
+			if (dockHostActor != null && dockHost == null)
+			{
+				var link = dockClient.AvailableDockHosts(dockHostActor, default, forceEnter, ignoreOccupancy)
+					.ClosestDock(self, dockClient);
+
+				if (link.HasValue)
+					dockHost = link.Value.Trait;
+			}
+		}
+
 		public override bool Tick(Actor self)
 		{
 			if (IsCanceling)

OpenRA.Mods.Common/Traits/DockClientManager.cs

@@ -177,16 +177,13 @@ namespace OpenRA.Mods.Common.Traits
 				if (target.Type != TargetType.Actor)
 					return;
 
-				if (IsTraitDisabled)
+				self.QueueActivity(order.Queued, new MoveToDock(
-					return;
+					self,
+					target.Actor,
+					null,
+					order.OrderString == "ForceDock",
+					true));
 
-				var dock = AvailableDockHosts(target.Actor, default, order.OrderString == "ForceDock", true)
-					.ClosestDock(self, this);
-
-				if (!dock.HasValue)
-					return;
-
-				self.QueueActivity(order.Queued, new MoveToDock(self, dock.Value.Actor, dock.Value.Trait));
 				self.ShowTargetLines();
 			}
 		}